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Upgrading the stock GPS antenna= more sats

Discussion in 'Phantom 2 Vision + Discussion' started by burlbark, Nov 6, 2014.

  1. burlbark

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    I thought I would give this a shot. I live in Northern Ca and have a difficult time finding more than 5 satellites at any given time. I dont have any drop issues I just have allot of trees, fog and clouds. Once I get above the trees I usually keep 6 sats locked. Well this just isnt enough. I did the foil mod, heatsinked the internal component of my wifi, used sniffer probes to analyze where interference was coming from. I tried everything to get more signal strength, and then it dawned on me to install a better antenna.

    The stock antenna GPS puck, is 2mm thick. The antenna utilizes its ground plane to gather more signal and the distance between the ground plane and the top of the antenna is a crucial measurement to allow more satellites at extreme angles to be recognized. I found that by removing a little plastic and swapping out the stock GPS antenna I could fit one in place with 1.5db passive gain. Since we are dealing with a signal strength of greater than -150db any db increase is going to be helpful.

    I had to remove the gps receiver and the heat the GPS antenna with a heat gun till it got hot to the touch. I then slid a knife blade between the antenna and the pcb. I used solder wicking copper braid on the antenna pin that pokes through the board. While keeping the pin hot I used the knife blade to remove the stock antenna. Out it came.

    The replacement antenna is not directional only the data is so I was able to clock the larger antenna to avoid the screw holes and had to remove a little plastic off the inside of the top. The replacement antenna is 2mm thicker.

    The results are not very scientific. I can however say that in an area that I only saw 5 satellites for 10-15 minutes at a time I saw 7 today for a brief period of time and stayed nearly rock solid with 6. This was on the ground not flying. I am sure once I get it back up in the air I will see many more. It was definitely worth the effort for me......

    Pics to follow when hughes net allows.... :x
     

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  2. flyNfrank

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    Very cool.

    Another member and myself have been talking about doing similar mods as you have described here. He is actually planning to do almost the same as what you just mentioned. Where I planned to moved my stock gps to the outside of the top cover rather then it being in it's default position. We're both just now ready to begin our missions. I believe he is waiting on a new gps puck, and I'm just a procrastinator. lol.

    I'm curious why you didn't try using the stock part instead of the route you did go?
     
  3. craigelinor

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    I would love to see pictures. Where did you get the replacement antenna? And which one? My Pv2+ is apart again as I keep playing with different foil mods to improve gps.Just ordered a stock replacement antenna from Digikey. The original had 2 obvious tears in the metal material.(pict) Not sure if it was affecting signal strength. I love your idea of improving the gps. what kind of solder did you use to resolder, does it matter? Thanks for sharing your idea. As a side note I have also read on gps antenna website that you want the shortest lead from gps antenna to main pc board, for what its worth.
     

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  4. Noël

    Noël Guest

    Just a thought. Will adding a 2nd GPS unit parallel over the original one not double the sensitivity?
     
  5. burlbark

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    The stock antenna is 2mm thick. This antenna Taoglas is 4mm thick and a had a signal gain of 1.5 db over stock.
     
  6. burlbark

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    No... it will act a a ground plain and and you should only then see the signal received by the top unit....
     
  7. job2310

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    flyNfrank this seems like a great idea for your mod if you don't see the results you want but just moving the stock module outside the shell.

    I'm going a little different route by using the NAZA-M V2 GPS puck mounted onto my bird with the standard mounting hardware. This might be a way to improve the reception further if I open the puck and upgrade that antenna.

    Seems like a market here where someone could sell upgraded GPS modules for people who aren't confident doing the mod themselves. :)
     
  8. burlbark

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    Shoot me a PM...... :D
     
  9. arizeda

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    Wonder what DJI are up to in this leaked pic of the Inspire.

    Check the F550, has 2 pucks
     

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  10. job2310

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    Inspire will be a tri-configuration so this isn't it. Place your bets folks!
     
  11. arizeda

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    Pretty sure that's it, but I'm sure there are many threads to discuss that :)

    Thoughts on the F550 in that pic?
     
  12. job2310

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    I'm thinking redundant flight control system rather than trying to prove GPS reception.
     
  13. arizeda

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    Perhaps. Interesting though!
     
  14. Noël

    Noël Guest

    Not on top, but next to it, parallel connected.
     
  15. burlbark

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    There is a larger antenna that could possibly be fitted.... Maybe down the road. It had like a 4db gain but was another quarter inch wider. I think I could get it in there and should have ordered it....

    I could not find room for another antenna and I think that it would cause emi issue emitting from one another and that may not enhance a clear signal.
     
  16. WyattEarp

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    Does anyone know if there is a replacement GPS that supports both Glonass and GPS satellites?
     
  17. job2310

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    I've never seen one. I remember seeing in another thread once where someone was going to have a play with this idea but I never saw an outcome.
     
  18. burlbark

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    The saw filter on the Gps receiver in the Phantom purposely cuts out weak data. This is a failsafe of sorts. By upgrading the passive antenna a person is not adding anything that would be conflicting to its already touchy flight controller.
     
  19. N017RW

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    I guess you could look at it that way.

    It might be more accurate to say they filter out out-of-band radio frequencies and boost the signal-to-noise ratio of the signal.
     
  20. justin00

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    Just trying to follow your instructions.. I'm a bit confused by the parts in bold. Would you be able to go into a little more detail please ? I'm guessing the heat gun is to loosen the adhesive, but a little confused by the part after that.. I've seen pics of the antenna connector on the gps, but yeah, I don't quite follow.

    Thanks again :]